Small Block Chevy Rocker Arms Compared
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- Опубліковано 3 лют 2023
- USRA recently announced a rule change allowing B Modified racers like myself to run full roller rockers arms. What does that mean and what are the implications? Watch to find out!
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I found .024 thousands differance between after market rockers which both claimed to be 1.6, so check how far your valve goes down with each, you may be surprised
I just purchased a set of Scorpion roller rockers for my small block project. It will take close to a month to receive them. They are manufactured in Florida, PRW, a decent rocker especially considering the price, come from overseas. I figured for Ferrea valves and over 7,000 rpm, I would go with the lifetime guaranteed Scorpion. I also like the color and the logo.About your valve float, I am running beehive springs and because the upper portion of the spring is a smaller diameter, it lessens the weight over the reciprocating mass giving better control along with the ovate wire. Beehinve springs stack from the bottom up as lift increases whereas coils compress mostly the same between all coils as they are squeezed. Valve float is most often of lack of spring control when the valve closes, it bounces off the seat abnormally. Most of the time it is an incorrect valve spring and not the rocker arm. Call Scorpion and ask them about your concern of valve float caused by a different rocker arm. Cheaper than a dyno test. (352) 512-0800
Have you been able to test your roller rockers yet? I installed them on our USRA bmod and now I’m struggling with a flutter around 6500. I’m wondering if I’m now short on valve spring pressure.
I have not. Getting ready to do a cam break in. Hopefully the end of this month we will get out on track. I do believe that the valve float may be an issue. In our first test I plan to start with the rev limiter at 6500 and creep it up slowly so we don't hurt anything
I would say. Most of the extra weight is in the bearing area which is not moving. Therefore not adding to mass to moving parts...👍
Good point. It's not just mass but distribution of mass which is relevant since the part is technically "rotating". I wanted to disassemble and weigh the rocker without the trunnion but I didn't have a small enough snap ring pliers. will get the right tool and follow up
@@rossracing6433 Good channel btw. I am working on a 307. A new challenge for me. Working on 64cc heads to replace the 75 cc heads. 0.016" head gaskets and 1.6 rockers similar to the stamped rollers like yours. In a 73 Nova
What about true rocker arm ratio? Stock is closer to 1:3 than 1:5. The roller tip is closer to 1.5 and the scorpion is a true ratio. Run the scorpion and get all of your cam lift. The mass of the rocker is on the stud. Not so much on the valve or pushrod. You will not need additional valve spring pressure with roller rockers according to Steve Morris.
how long does it take for the oil to get to the roller tiped second rocker
Like for priming the engine? Or just in general? Small block Chevy stock blocks oil the cam first, so it gets there pretty quick as long as everything is set up right. Doesn't really matter what kind of rocker you run. Although since the full roller needs less oil some guys run restrictors to help keep oil going to other places where it's more needed
@@rossracing6433 Thanks for the reply.....I think this is very important so i need to explain myself better.....I will use another video to show
you what i mean and see how the oil sits in the middle of the rocker and never spills over to the tip to lube it.
ua-cam.com/video/sp1jlzG-RXM/v-deo.html
Ahhh I see what you mean now. Yes that is a potential issue I suppose. At high spring pressures often times the roller just slides across the top of the valve rather than actually rolling so lubrication to that point is critical. Even if most of the oil goes to the ball, there's quite a lot of oil being slung around under the valve covers. We run shields over the top of the rockers to help reflect that oil back onto the rocker and onto the springs for cooling, so that helps. Personally I've never seen a failure related to insufficient oil at the roller tip, but anything is possible
hi there , is these interchangeable or you need a special setup to install them on old classic chevy 350
For the most part they are interchangeable. The full roller rockers may require a taller valve cover as they're a little bulkier.
@@rossracing6433 thanks for replaying, does these effect the performance of the engine or damage it in any way as my engine is stock.
@@ramthaLord on a stock engine you're not likely to see any noticable increase in performance. If you change to rocker that is higher than the stock 1.5:1 ratio, you should check retainer-to-guide, coil bind, and piston-to-valve clearance as though you were installing a larger camshaft
Not just weight, but big trunion bearings last longer because the spring load is spread over more bearings,andit just sits and rocks, so just because a rocker weighs more all that weight is not transfered to the valve train ! Study the science before assuming things. Hope this helps! GOD bless .
50 times out of a Second?
The cam spins half the speed of the crank. If the crank spins 6000 times per minute, that's 100 times per second. That means the valve opens and closes 50 times per second at 6000 rpm.